Precoated filter for the filtration of flowing media

ABSTRACT

In a particularly noise-free and vibration-free operating precoated filter for filtering for example cooling lubricating means, a filter candle  12  surrounding a riser channel  16  is mounted by means of a riser tube  15  in a separating plate  5  in an axially moveable manner. A filter cake adhering to the outside of the filter candle  12  is loosened in such a manner that for example a disk-shaped rotary body  40  comprises a shoulder  42  between the track end  43  and the track start  44  along its track  41.  As soon as a head end piece  20  connected to the riser tube  15  and moveable in an axial manner against the force of a spring  21  is released from the rotating track end  41,  the stored force of the spring  21  accelerates the filter candle  12,  so that the filter cake adhering to the filter candles is loosened by the acceleration of the filter candle  12  and the impact pulse when a dampening ring arranged between the filter candle  12  and the separating plate  5  abuts the separating plate.

[0001] The invention relates to a precoated filter for the filtration offlowing media, in particular lubricating and cooling lubricating meansaccording to the preamble of claim 1.

[0002] From DE-PS 28 28 967 is known a generic precoated filtercomprising a separating plate arranged in the filter housing, and whichseparates the filter housing into a lower filtrant chamber and an upperfiltrate chamber, to which plate are connected filter candles whichenclose a riser channel connecting the chambers for catching solids fromthe medium. With this precoated filter, the filter cake consisting ofthe filtered solids and contaminants deposited at the filter candles isloosened by means of introducing pressurized gas, for example dried to aresidual moistness of 50%, and is subsequently loosened with a devicespecially devised therefore. The device for loosening the filter cakeconsists of a knocking device which is arranged at the head of thefilter housing and which comprises a plunger which is guided through ahousing passage of the filter housing in a sealed manner and which iscoupled to the separating plate. So as to achieve a loosening of thedried filter cake from the filter candles, one has to use forcefulimpact pulses of the knocking device which lead to noise disturbance andvibrations and impact stresses in the precoated filter. So as to avoid atransfer of the impact and knocking pulses to the plant parts, to whichthe precoated filters are mounted, the generic precoated filters have tobe placed on elastic vibration dampers.

[0003] It is a particular object of the invention to create a precoatedfilter for dry filter cake discharge, which operates in a particularlynoise-free and vibration free manner.

[0004] This object is solved by the invention given in claim 1.According to the invention it is provided that the device for looseningthe filter cake comprises a rotary body, with which the filter candlescan be loaded with a pulse individually or in a group. The measuresaccording to the invention lead to a monumental noise and vibrationreduction, as with the pulse produced by means of the device, not theseparating plate as a whole, but only individual filter candles, thatis, noticeably smaller masses are loaded.

[0005] In a preferred embodiment, the rotary body for producing thecleaning pulse comprises at least one shoulder in the form of a step.Due to the shoulder in form of the step, the filter candles which havepassed the shoulder edge during a rotation of the rotary body areaccelerated. Afterwards, the filter candles abut the separating plate orthe rotary body, so that a pulse is produced which is sufficient forloosening the filter cake, on one hand by the acceleration, and on theother hand by the abutment or impact. It is nevertheless preferred thatthe filter candles do not abut the rotary body when moving backwards, sothat the rotary body does not need a special bearing or dampening. For asimple construction of the precoated filter, the rotary body should bearranged in the filtrate chamber.

[0006] Preferably it is provided that the filter candles are arrangedaround a center axis in a concentric manner, whereby the rotary body cancomprise a common or a separate circular track with a shoulder in theform of a step for each concentric filter ring. By the arrangement ofseveral filter candles, the filter performance of the precoated filtercan be increased. In one embodiment, it can be provided that the tracksare formed in a helical manner. By the helical design, the position ofthe filter candles is changed continually until the edge of the shoulderof the rotary body passes over the filter candle, so that theacceleration pulse is introduced into the filter candle. With a trackincreasing continually along the circumference, the filter candles arecleaned once per rotation of the rotary body.

[0007] In an alternative embodiment of the precoated filter, the rotarybody comprises several shoulders, whereby more shoulders can be arrangedon circular paths with a larger radius than on circular paths with asmaller radius. In this embodiment, a higher filter candle density canbe used on the circular paths with larger radius, whereby these filtercandles are possibly cleaned several times during one rotation of therotary body.

[0008] The rotary body can be a disk, and the one or several shouldersin the tracks form a displacement between the track end and a trackstart. Preferably, the disk can comprise apertures in the shape ofsegments in the flat side of the disk, so that part of the filtrate canpass through the disk and can possibly exit by means of an outletarranged above the rotary body. The latter can alternatively also beachieved in that several helical rings which are connected by radialwebs form the rotary body. With a rotary body formed in such a way,recesses are already present due to the construction, so that thefiltrate can pass through the rotary body.

[0009] A simple construction of the precoated filter and the filtercandles results when the riser channel ends in an upper head piece whichis mounted at the separating plate in an axially moveable manner andwhich can be moved in the axial direction by means of the tracks. Therotary body then glides with its tracks along the head pieces andpresses against these, until the head pieces have reached the shoulderin the form of a step. The riser channels and the filter candles arecontinually pushed away from the separating plate during rotation of thetrack and are preferably pushed into the filtrant chamber. This possiblyuniform displacing movement is suddenly reversed when the shoulder inthe form of a step has slid past the head pieces. For producing theforce for moving the filter candles back, it is preferably provided thatan energy store as for example a spring is provided between the headpiece or the head end piece and the separating plate, whereby the energystorage device will be loaded by the axial movement of the head pieces.

[0010] In a particularly preferred embodiment the head piece is mountedin the separating plate by means of a sleeve which projects from thelower side of the separating plate by means of a sleeve projection. Bymeans of the sleeve projection, a comparatively long guide of the risertubes or head pieces is achieved in the separating plate, so that theaxial guide of the filter candles in the separating plate will not bedisplaced, even after numerous operating hours. Furthermore, it isadvantageous that the filter candles do not immediately abut theseparating plate, but the front end faces of the sleeves. For reducingthe frictional forces between the rotary body and the head piece or thehead end piece, their front ends cooperating with the tracks of therotary body can be formed in an arcuate manner, preferablysemi-spherical.

[0011] So as to reduce the vibrations and noises produced when thefilter candles return into their starting position, a preferablycircular or hollow frustoconical dampening body can also be arrangedbetween the filter candle and the separating plate, which can at leastdampen the noise production when the filter candles abut the separatingplate intermittently. Furthermore, the separating plate can be mountedin the wall of the housing or can be screwed to a flange ring securedthereto, whereby dampening materials are then arranged between theseparating plate and the wall of the housing. By this measure, the noiseproduction is further reduced with a comparatively simple filterconstruction and simple filter exchange.

[0012] Due to the shoulders provided according to the invention forreleasing the kinetic energy stored in the springs, only one directionof rotation is allowed for the rotary bodies. The device can suitablycomprise a freewheeling arrangement such as a sleeve freewheelingarrangement or a ratchet freewheeling arrangement for the rotary body,which excludes an erroneous function or a wrong direction of rotation ofthe rotary bodies even after their exchange.

[0013] So as to achieve large filter areas, a multiplicity of filtercandles can be arranged in a filter housing. With these embodiments, itis recommended that the cleaning mechanism for loosening the solidscomprises several rotary bodies, which can preferably be driven by meansof a single common drive. For avoiding large speeds, and/or rotaryspeeds of the rotary bodies, which are unfavorable for the drive or theflow of the rotary bodies, a modular construction can be advantageouswith precoated filters having a particularly large total filter area,whereby several filter candles, which are arranged concentrically arounda field axis, form a filter candle field, and a rotary body mounted onthe housing top on the field axis by means of shaft ends is assigned toeach filter candle field. The shafts of the rotary bodies can then becoupled to the centrally arranged drive shaft in a simple and costeffective manner by tensioning means such as cog belts or V-belts or bygear wheels, so as to rotate with the same speed during operation.

[0014] In an alternative embodiment, the filter candles can be arrangedin a concentric manner around a center axis, and the device comprisestwo rotary bodies which rotate by means of a gear, preferably atensioning gear, with different speeds. It is then particularlyadvantageous to choose the translation of the speed of the gear in sucha manner that the rotary bodies comprise the same circumferentialvelocities, so that unfavorable cross flows or vortices are avoided inthe filtrate chamber. With this, it is recommended to connect one rotarybody in a non-rotary manner to the drive shaft, and to mount the secondrotary body in a rotary manner at the drive shaft.

[0015] So as to reduce the operating and servicing costs of theprecoated filter in spite of the large friction forces between the trackand the head end piece, the cap-shaped head end pieces can glide alongthe track, and are therefore prone to wear, can be exchanged, and can inparticular be formed as screw pins which can be threaded into the capplates, provided with a rounded head and possibly be hardened at thehead. The tracks can preferably be formed by exchangeable ring segmentelements which are releasably mounted at the rotary body. Theexchangeable elements can also reduce the production costs and costs ofspare parts if they are used with precoated filters having differenthousing dimensions, that is, with rotary bodies having different widths.Every rotary body can advantageously comprise at least two wings,mounting plates or the like, which are mounted in an oblique manner toone another and to the separating plate and/or two counter-rotatingobliques for mounting the exchangeable elements, so that the ringsegments can comprise a uniform depth respectively, and the storage ofthe kinetic drive energy for the cleaning pulse is achieved by theangled position of the wings or obliques of the rotary body.

[0016] Further advantages and embodiments of the invention result fromthe following description of the drawing, in which exemplary examplesare illustrated.

[0017] In the drawings:

[0018]FIG. 1 is a schematic cross-section through a precoated filteraccording to the invention;

[0019]FIG. 2A is a detailed section of a filter candle mounted in theseparating plate before the introduction of the pulse;

[0020]FIG. 2B ist the view from FIG. 2A immediately after theintroduction of the pulse;

[0021]FIG. 3 is a perspective embodiment of a rotary body;

[0022]FIG. 4 is a sectional view according to IV-IV in FIG. 3;

[0023]FIG. 5 is the mounting of the separating plate in the wall of thehousing;

[0024]FIG. 6A is a second embodiment of the filter candle mountingaccording to FIG. 2A;

[0025]FIG. 6B is the embodiment according to FIG. 6A immediately afterthe introduction of the pulse;

[0026]FIG. 7 is the construction and drive concept for a modifiedprecoated filter having two rotary bodies;

[0027]FIG. 8 is the construction and drive concept for a modularprecoated filter having several rotary bodies and a large total filterarea; and

[0028]FIG. 9 is an alternative embodiment for a rotary body withexchangeable tracks.

[0029] The precoated filter shown schematically and designated as 10 forfiltering of for example lubricating means or cooling lubricating meanscomprises a cylindrical filter housing 1 with a lower housing part 2 andan upper housing part 3. The two housing parts 2,3 are connected to oneanother in a detachable manner by means of a threaded flange 4. Aseparating plate 5 arranged in the inside of the filter housing 10 inthe separating plane between the lower housing part 2 and the upperhousing part 3 divides the inner chamber of the filter housing 1 into alower filtrant chamber 6 and an upper filtrate chamber 7. An inlet 8leads into the filtrant chamber 6 for the medium to be filtered.Correspondingly, the filtrate chamber 7 comprises an outlet 9, so as tolet the filtered filtrate flow back for example into a lubricating meanscycle, not shown. At the bottom of the lower part 2 of the housing isarranged a pivotal throttle valve 11, so as to be able to discharge thefilter cake 13 which was previously dried by means of a drying device,not shown, i.e. an introduction of pressurized gas.

[0030] The separating plate 5 is realized as a sieve plate with acorresponding number of bores 14 arranged concentrically around thecenter axis A. The bores 14 are passed through by riser tubes 15, whichare enclosed by filter candles 12 below the separating plate 5, so thatfiltered liquid enters the inner chamber of the filter candles 12through the filter fabric of the filter candles 12, rise in a riserchannel 16 of the riser tubes 15 and can transgress into the filtratechamber 7 as filtered filtrate by means of exit bores 27 (FIG. 5), notshown in FIG. 1. Thereby, the riser channel 16 connects the filtrantchamber 6 and the filtrate chamber 7. The individual filter candles 12are mounted in the sealed bores 14 in an axially moveable manner bymeans of the riser tubes, as will be explained further.

[0031] The filter candles 12′ on the left side in FIG. 1 are displacedaxially further into the filtrant chamber 6 relative to the filtercandles 12 on the right side of FIG. 1, so that the stop formed by ahead plate 18 and a dampening ring 19 of the filter candles 12 is spacedin the left half of FIG. 1 from the lower side 5′ of the separatingplate 5, while the dampening ring 19 lies immediately at the lower side5′ of the separating plate 5, with the filter candles 12 shown on theright side of FIG. 1. So as to provide an energy storage device and tobias the filter candles 12, 12′ in their hanging arrangement inside thefilter housing 1, springs 21 are arranged between the separating plate 5and the cap-shaped head end sections 20 of the riser tubes 15 within thefiltrate chamber 7. The axial movement (backward movement) of the filtercandles 12 is limited in the direction V of the arrow by means of thestop formed by the dampening ring 19 and the head plate 18.

[0032] As FIG. 1 shows further, a filter cake 13 adheres to the outercircumference of the filter candles 12′ on the left side of FIG. 1,while the filter cake 13′ of the filter candles 12 shown on the rightside of FIG. 1 was already loosened. So as to achieve the loosening ofthe filter cake 13′, and therewith a cleaning of the precoated filter10, a cleaning device designated as 30 is provided, which includes anelectronic drive 31 arranged outside the upper part 3 of the filterhousing, the drive shaft 32 of which is mounted in a rotary passage 33arranged centrally at the upper part 3 of the filter housing. The lowerend of the drive shaft 32 is connected to a rotating disk in anon-rotary manner, which can rotate within the filtrate chamber 7. Thedisk 40 comprises, as can schematically be seen in FIG. 1, a helicaltrack 41 at the lower flat side 41′ of the disk, so that a shoulder 42in the form of a step climbs between a track start designated as 44 anda track end designated as 43. The shoulder 42 formed at a right angle toa back side 41″ of the disk forms thereby a displacement between thetrack start 44 and the track end 43, as can be seen schematically in theright half of FIG. 1.

[0033] As the disk 40 rotates, the head pieces 20 glide with their frontends 29 along tracks 41 and are continually lifted by the helical climbof the track from the position according to FIG. 1 in the right half tothe position in left half shown in FIG. 1, until they abut the track end43 with the head end pieces 20 when the spring 21 is fully tensioned.This state can best be seen in FIG. 2A, which is referred to now. Thecap-shaped head end piece 20 has been displaced towards the separatingplate 5 during the rotary movement of the disk 40 in the direction R ofthe arrow by means of the continually decreasing distance between theseparating wall 5 and the track 41 against the force of the spring 21,so that, according to FIG. 2A, the filter candle 12 or the frustoconicalsealing ring 19′ has reached its maximal distance from the lower side 5′of the separating plate 5. As the disk 40 rotates, the disk 40 reachesthe position shown in FIG. 2B immediately thereafter. The head endsection 20 does not abut the track 41 anymore, as the track end 43 hasmoved away. The spring force previously stored in the spring 21 canunload in the direction V of the arrow, and the filter candle 12,together with the riser tube 15 and the head end section 20 canaccelerate in the direction V of the arrow. This acceleration pulse isabruptly slowed down when the filter candle 12 with the frustoconicaldampening ring 19′ abuts the lower side 5′ of the separating plate 5.

[0034] This state is shown in FIG. 2B as well as in the right half ofFIG. 1, to which it is referred to again. As can be seen in FIG. 1, thefilter cake 13′ is loosened from the outer casing of the filter candles12, on the one hand by means of the acceleration movement of the filtercandles 12, on the other hand by the abutment pulse of the filter candle12 against the lower side 5′ of the separating plate 5, so that it fallsdownwards and can be discharged via the throttle valve 11. In theembodiments shown, the distance between the track start 44 and theseparating plate 5 is dimensioned in such a way that the head end pieces20 at the end of the backward movement do not abut the rotary body 40,that is, that no pulse is transferred to the rotary disk. Therefore, itis preferably provided that a gap 46 remains between the front end 29and the track region 41 close to the track start 44, when the filtercandles 12 return to their starting plates.

[0035] As the disk 40 driven by the electronic drive 31 moves awaycontinually, all filter candles 12, 12′ arranged in the filter housingare initially pretensioned by means of the climbing track 41 during arevolution of the disk 40 of 360°, are afterwards loaded by the shoulder42 in the form of a step by means of a pulse, so that the filter cake13, 13′ can fall off from all the filter candles 12. As the filtercandles are only loaded with the pulse individually or in a group, thenoise disturbance as well as the vibrations produced during cleaning arenoticeably smaller than in the state of the art. This result is achievedin particular by the use of the rotary body (disk 40) with a shoulder 42in the form of a step.

[0036] The construction and the mounting of the filter candles at theseparating plate 5 is now explained in more detail with regard to FIGS.2A and 2B. As FIGS. 2A, 2B show, the filter fabrics 17 of the filtercandles 12 enclose a hollow riser tube 15 which comprises a riserchannel designated as 16 on the inside. The filter fabrics 17 of thefilter candles 12 are closed at their ends, and are mounted at theirupper ends, shown in FIGS. 2A and 2B, to a multi-piece head plate 18provided with an inner thread 22. The riser tube 15 comprises an outerthread 23 at its upper end, so that the head plate 18 and the riser tube23 can be screwed to one another. A head section 24 is screwed to theouter thread 23, which is mounted in a sleeve 25 in an axially moveablemanner, which is screwed into a bore 14 of the separating plate 5. AnO-ring 26 prevents that liquid can pass between the sleeve 25 and thehead section 24. The riser channel 16 discharges into exit bores 27which are distributed around the circumference and from which filtrateflows into the filtrate chamber 7. The hollow frustoconical dampeningbody 19′ is clamped between the head plate 18 and an annular shoulder 28at the lower end of the head section 24.

[0037]FIGS. 3 and 4 show an alternative embodiment for a rotary body.The rotary body designated as 50 is for example produced as a moldedpart made of metal and comprises an inner helical ring 51 and an outerhelical ring 52, which form tracks 53 or 54 with their upper frontareas. The rings 51, 52 are connected by radial webs 55, 56, 57, 58, sothat recesses 59 in the shape of segments result between two webs 55,56, 57, 58. In FIG. 3 a shoulder 60 in the form of a step can be seen,which is added to the shoulder edge 61. The shoulder 60 forms thetransition between the track starts 63 and the track ends 64, whichcoincide with the shoulder edge 61. The drive coupling of the rotarybody 50 to the drive shaft of the electronic drive takes place at thecenter hole 70, for example at its peripheral wall 71 or at the backside of the peripheral wall 71 in a manner not shown. The helical tracks52, 53 effect the displacement and pretensioning of the filter candlesor head end pieces of the filter candles such as the loading of thesprings 21, as has previously been explained with regard to FIGS. 1 and2A, 2B.

[0038]FIG. 5 shows the positioning of the separating plate 5 in thedividing plane between the lower end 2 of the housing and the upper end3 of the housing in an exemplary manner. The separating plate 5comprises an annular groove 35 at its outer circumference, in which anO-ring 36 is arranged, so as to seal the separating plate 5 at thecircumference against the upper part 3 of the housing. So as to dampenthe vibrations and noises produced when the filter candles 12, not shownhere, abut the separating plate, a first dampening ring 37 is insertedbetween the upper front end 70 of the lower part 2 of the housing andthe separating plate 5, and a second dampening ring 38 is insertedbetween a radial shoulder 71 of the upper part 3 of the housing and theseparating plate 5. The separating plate 5 comprises a ring-shapedrecess facing the radial shoulder 71. FIG. 5 also shows that thecap-shaped head end section 20 of the head section 24 comprises a capplate 20′ formed as a nut and that the sleeve 25 is also provided with anut having several edges, with which the filter candles can be mountedor dismounted in the bores of the separating plate, not shown here.

[0039]FIGS. 6A, 6B show a particularly advantageous and reliableembodiment for the filter candles and their positioning in theseparating plate 105. Parts different from the above description areprovided with reference numerals which are increased by 100. The bores114 in the separating plate 105 have a diameter which is the same orlarger than the outer diameter of the filter candles 12 or the dampeningrings 19′. Sleeves 125 with relatively solid sleeve walls are screwedinto the bores 114. The sleeves 125 comprise sleeve projections 180 inone piece which project beyond the lower side 105′ of the separatingplate. The sleeve projections 180 provide a relatively long guide of thehead pieces 124, so that, even after numerous cleaning pulses, thefilter candles 12 in the separating plates 105 do not move about. Asparticularly shown in FIG. 6B, the widening and the elongation of thesleeves 125 also effects that the dampening rings 19′ abut the front endsides 181 of the sleeve projections 180, and therefore no more the lowerside 105′ of the plate. Furthermore, the friction contact between thehead pieces 124 or the head end pieces 120 and the tracks 41 of therotary bodies 40 is reduced considerably. That is, the head end pieces120 with their front ends 129 cooperate with the tracks 41 only atpoints.

[0040]FIG. 7 shows a precoated filter 100 with a separating plate 105,which is mounted with a distance underneath the separating plane betweenthe lower part 102 of the housing and the upper part 103 of the housingforming the top to a flange ring 110 formed in the inside of the lowerpart 102 of the housing and comprises bores 114 which are arrangedconcentrically around a center axis, into which are mounted filtercandles, not shown; the mounting and arrangement of the filter candlesbeing identical to the embodiment described above. Two rotary bodies140, 150 are arranged in the filtrate chamber 107, which haveessentially, with regard to the tracks 143, 144, 153, 154, shoulders anda cleaning pulse production with the same construction and the same modeof operation as the rotary body described with regard to FIG. 3, so thata new description does not have to take place. The inner rotary body 140rotates in the ring area spanned by the outer rotary body 150 and itstracks 143, 144 are assigned to filter candles arranged on inner filtercycle paths. In the shown embodiment, the inner rotary body 140 isconnected to a drive shaft 132 in a non-rotary manner, which passescentrally through the top 103 of the housing, is mounted thereto withthe sealing shaft passage 133, and is driven by means of the electronicdrive, not shown. The outer rotary body 150 is mounted at a shaftshoulder 134 of the drive shaft 132 in a suitable manner by means of theball bearings 171 mounted in the center hole 170, so that it can rotatefreely around the drive shaft 132. The rotary bodies 140, 150 arecoupled to one another by means of a gear drive shown by means of belts180; the belt 180 surrounds the shaft of the drive shaft 132 and theshaft of a transmission shaft 181 which is mounted by means of amounting arrangement 182 to the top 102 of the housing. The lower end183 of the transmission shaft 181 is provided with external teethengaging a tooth comb 156 at the back of the rotary body 150, so as totransfer the rotation of the drive shaft 132 to the outer rotary body150. With the gear, a speed translation is produced which is chosen insuch a way that the circumferential velocities of the inner rotary body140 and of the outer rotary body 150 are about the same, that is, aspeed translation which is reciprocal to the ratio of the diameters ofthe rotary bodies 140, 150. By this measure, the circumferentialvelocity of the outer rotary body can be reduced to a size which isacceptable for flow and drive, even with several filter cycles.

[0041]FIG. 8 shows a precoated filter 200 having a large filtrationperformance due to the large dimensions and the large number of filtercandles. As with the previously described embodiment, a separating plate205 is supported on a flange ring 207 in the lower part 202 or thehousing. The bores 214 receiving the filter candles are arrangedconcentrically around a corresponding field center axis M with theirfilter candle fields F shown by dotted lines. A rotary body 240 isassigned to each filter candle field F, which is connected in anon-rotary manner to a shaft end 281 which is arranged on the centeraxis by means of the bearing arrangement 282 at the top 203 of thehousing. In FIG. 8 several filter candle fields F and rotary bodies 240are arranged symmetrically around the central rotary body 240A, which isconnected to the drive shaft 232. The rotary bodies 240, 240A have anidentical construction and their functional operation corresponds tothat of the rotary bodies described with regard to FIG. 3. By means ofthe modular construction using several rotary bodies 240, the number ofthe present filter candles is hardly limited. The circumferentialvelocities of the individual rotary bodies 240 are relatively low andare coupled to their speed by means of the shaft ends 281 and the driveshaft 232 surrounding the transfer belts 280A, 280B.

[0042]FIG. 9 shows a further alternative embodiment of a rotary body350, which can be used with all previously described embodiments of theprecoated filter. The rotary body 350 consists of a cylinder body 351connected to the drive shaft 332 in a non-rotary manner, at the outerwall 352 of which are secured wing-shaped mounting plates 353A, 353B.The cylindrically formed inner sides 354 of the mounting plates 353A,353B abut the outer wall 352, whereby supporting ribs 355 are welded,adhered or formed between the upper sides of the mounting plates 353A,353B and the outer wall for stiffening the connection. The mountingplates 353A, 353B are arranged in an angular manner to one another andto a plane perpendicular to the drive shaft axis, so that they areoblique to the separating plate, not shown, in the mounting state of therotary body 350. Ring segment elements 357 (claws) are arranged in anexchangeable manner at the lower sides facing the separating plates bymeans of screws 360 which form tracks for the head end pieces of thefilter candles during operation. For filter candles which are arrangedfurther inwardly, the rotary body comprises separate ring segmentelements 359, the dimensions and radii of which are smaller than thoseof the ring segment elements 357. For mounting these inner ring segmentelements 357 by means of screws 361 at the desired angle, the lower sideof the cylinder is provided with two counter-rotating obliques 363A,363B, each forming a half of the lower side of the cylinder, thedeclination essentially corresponding to the declination of the mountingplates 353A, 353B. Due to the angular mounting of the mounting plates orthe obliques, the head end pieces of the filter candles can contact thetracks without impact and are then pressed downwards with progressingrotation of the rotary body 350 while storing the energy necessary forthe cleaning pulse in the energy storage device until they reach thecorresponding element end 358, 364, that is, the end of thecorresponding tracks, and transform the kinetic energy stored in theenergy storage device into movement energy.

[0043] It is clear that preferred exemplary embodiments were explainedhere. Not shown, but part of the protection, should also be embodimentsin which several shoulders in the form of steps are arranged along atrack or on the flat side facing the head end sections of the rotarybodies. The shoulders can also be formed by cams or the like or with asteep tear-off edge. There are numerous variations for the constructionof the housing and the arrangement of the seals for the expert, whichshall be included in the protection. The outlet can also be arrangedoutside the housing, in which an exit cross-section is provided in orbehind the rotary passage. The separating plate can also be screwedagainst a flange ring with intermediate positioning of the dampeningmaterials, which is secured or formed at the inner side of the housing.With this embodiment, the separating plate is then not in but below thedividing plane of the housing parts, and the second housing part servesas the upper closing top.

1. Precoated filter for filtering flowing media, in particularlubricating and cooling lubricating means comprising a separating platearranged in the filter housing and separating the filter housing into alower filtrant chamber and an upper filtrate chamber, to which areconnected filter candles which enclose a riser channel connecting thechambers for catching contaminations or solids from the medium, andwhich comprises a device for loosening the solids dried to a filtercake, characterized in that the device comprises a rotary body (40; 50),with which the filter candles (12) can be loaded with a pulseindividually or in a group.
 2. Precoated filter according to claim 1,characterized in that the rotary body (40; 50) for producing the pulsecomprises at least one shoulder (42; 60) in the form of a step forproducing the pulse.
 3. Precoated filter according to claim 1 or 2,characterized in that the rotary body (40; 50) is arranged in thefiltrate chamber.
 4. Precoated filter according to one of claims 1 to 3,characterized in that the filter candles (12) are arranged in aconcentric manner around a center axis, whereby the rotary body (40; 50)comprises a circular track (41; 53, 54) with a shoulder (42; 60) in theform of a step for each concentric filter ring.
 5. Precoated filteraccording to claim 4, characterized in that the tracks (41; 53, 54) havea helical shape.
 6. Precoated filter according to one of claims 1 to 5,characterized in that the rotary body comprises several shoulders,whereby tracks with a larger radius preferably have arranged thereonmore shoulders than tracks with a smaller radius.
 7. Precoated filteraccording to one of claims 1 to 6, characterized in that the rotary bodyis a disk (40) and the shoulder or the shoulders (42) form adisplacement (42) between track parts (43, 44) at the flat side (41′) ofthe disk formed at the tracks (41)
 8. Precoated filter according toclaim 7, characterized in that the disk preferably comprises aperturesin the shape of segments in the flat side of the disk.
 9. Precoatedfilter according to one of claims 1 to 8, characterized in that severalhelical rings (51, 52) which are connected by radial webs (55, 56, 57,58) form the rotary body (50).
 10. Precoated filter according to one ofclaims 1 to 9, characterized in that the riser channel (16) ends in anupper head piece (24; 124) which is mounted to the separating plate (5;105) in an axially moveable manner, and which can be moved in the axialdirection by means of the tracks (41; 53, 54).
 11. Precoated filteraccording to claim 10, characterized in that an energy storage devicesuch as a spring (21) is provided between the head piece (24; 124) or ahead end piece (20; 120) and the separating plate (5) which can beloaded by the axial movement of the riser channel.
 12. Precoated filteraccording to claim 10 or 11, characterized in that the head piece (124)is mounted in the separating plate (105) by means of a sleeve (125),which projects beyond the lower side (105′) of the separating plate bymeans of a sleeve projection (180).
 13. Precoated filter according toone of claims 10 to 12, characterized in that the head piece (124) orthe head end piece (120) comprises a preferably semi-spherical arcuatefront end (129) cooperating with the rotary bodies (40; 50). 14.Precoated filter according to one of claims 1 to 13, characterized inthat a preferably ring-shaped or hollow frustoconical dampening body(19; 19′) is arranged between the filter candle (12) and the separatingplate (5; 105) or the sleeve front face (181).
 15. Precoated filteraccording to one of claims 1 to 14, characterized in that the separatingplate (5; 105) is mounted in the wall (2, 3) of the housing or in aflange ring formed or secured at the wall of the housing, wherebydampening materials (36, 37, 38) are arranged between the separatingplate (5; 105) and the wall (2, 3) of the housing or the flange ring.16. Precoated filter according to one of claims 1 to 15, characterizedin that the rotary body (40; 50) can be driven by means of an electronicdrive (31) arranged outside of the housing (1).
 17. Precoated filteraccording to one of claims 1 to 16, characterized in that the tracks(41; 53, 54) climb continually from the track start (44; 63) to thetrack end (43; 61, 64).
 18. Precoated filter according to one of claims1 to 17, characterized in that the device comprises a freewheelingarrangement such as a sleeve freewheeling arrangement or a ratchetfreewheeling arrangement for the rotary body.
 19. Precoated filteraccording to one of claims 1 to 18, characterized in that the device forloosening the solids comprises several rotary bodies (140, 150; 240,250), which can preferably be driven by means of a single common drive.20. Precoated filter according to one of claims 1 to 19, characterizedby a modular construction, whereby several filter candles which arearranged concentrically around a field axis form a filter candle field(P), and a rotary body mounted on the field axis (M) by means of theshaft ends (281) at the top of the housing is assigned to each candlefield (F), whereby the shafts (281) of the rotary bodies are preferablycoupled to the particularly centrally arranged drive shaft (232) bytensioning means such as cog belts or V-belts or gears and circulatewith the same speeds during rotation.
 21. Precoated filter according toone of claims 1 to 19, characterized in that the filter candles arearranged concentrically around a center axis and that the devicecomprises two rotary bodies (140; 150) which rotate by means of a gear;preferably a tension gear (180), with different speeds, whereby thespeed translation of the gear is preferably chosen in such a way thatthe rotary bodies (140; 150) comprise the same circumferential speeds.22. Precoated filter according to claim 21, characterized in that onerotary body (140) is connected to the drive shaft (132) in a non-rotarymanner and that the second rotary body (150) is mounted at the driveshaft (132) in a rotary manner.
 23. Precoated filter according to one ofclaims 1 to 22, characterized in that the head end pieces can beexchanged and are formed in particularl as screw pins which can bescrewed into the cap plates, provided with a rounded head and possiblyhardened at the head and/or that the tracks are formed by exchangeablering segment elements (357, 359) which are secured to the rotary body ina detachable manner.
 24. Precoated filter according to claim 23,characterized in that the rotary body (350) comprises at least twowings, mounting plates (353A, 353B) or the like which are oblique to oneanother and to the separating plate, and/or two obliques (363A, 363B)which are arranged in a counter-rotating manner with regard to oneanother for securing the exchangeable elements (357, 359).